Drill jar



I Mar..13, 1923.

J. D. GIBBS DRILL JAR I Filed Jan.

Patented Mar. 13, 1923.

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DRILL JAR.

Application filed January 6, 1922. Serial no 527,474.

To all whom it may concern Be it known that I, Lines 1). GIBBS, .a citizen of the 'Unitedstatea'and resident of Louisville, clientucky, have invented certain new and useful Improvements in Drill Jars, of which the following is a specification.

My present invention relates to improvements in drill jars for use in connection with well drills and aims to provide a,

strong, durable construction in which the formation of any hydraulic cushion will be prevented and at the same time will be free from liability of becoming clogged by dirt or mud conveyed by the flushing water. 0

With these and other objects in view, the invention includes'the novel features of construction and arrangement and combination of parts hereinafter described and particularly defined by the appended claims.

A drill jar constructed in accordance with my invention is illustrated in the accompanying drawing, in which-- Figure 1 is a side elevation of the im proved jar.

Fig. 2 is a longitudinal section on line 2-2 of Fig. 1; and

Fig. 3 is a transverse section on line 33 of Fig. 2.

Referring by reference characters to this drawing, it will be observed that my improved drill jar comprises two elements, to wit, a cylinder member 1 and a piston member 2. The cylinder member 1 is adapted at it lower end to be-connected with a drill rod section by means such as the threaded socket 1, being also provided adjacent its lower end with a squared portion 1 for the application of a wrench.

The piston member 2 is provided at its upper end with similar means for drill rod attachment, as for instance, the threaded portion 2 and is also provided with a squared portion for wrench application indicated at 2*. The cylinder member is hollow for the greater portion of its length and in the upper portion thereof is provided with what I term a piston chamber indi cated at 1 which terminates at its lower end in an annular internal shoulder o. The cylinder member is provided at itsupper end with a removable cap 3 preferably in the shape of a screwed bushing through which the piston member slidably passes, the

lower end of the bushing forming an upper stop abutment which is spaced 'a suitable distance from the lower shoulder or abut ment- 0.

The portion of the cylinder member be low the shoulder 0 is provided with an in- .teri'i-a'l bore or what 1 term a guide cavity indicated at l which terminates at its lower end in a port communicating with the outside of the cylinder member which port is preferably of curved andjflaring shape as indicated at 1 The piston member has a shank portion, 2- which passes'through the bore of the bushing. 3 with an accurate slidable fit and is provided with an enlarged-or inrpact portion 2 the? upper and; lower shoulders (Z cl of which are adapted to contact alternately with the abutments formed by the annularshoulder c at the bottom and the end of the bushing 3 at the top, it being observed that the distance between the said annular shoulder c and the-bushing is of sufiicient length to give the requisite lost motion connection to impart the necessary 1 impact orjar to the drill stem.

The portion 2 of the piston member below this enlargement fits the bore or cavity 1 with an accurate but sliding engagement. As these drill jars work at considerable depth submerged in the flushing water, which is present in the well, it is impossible to keep water from penetrating the jar no matter what its construction may be. and to permit the free passage of waterin the piston chamber to opposite sides of the enlarged or impact portion 2 I make this portion of longitudinal fluted or grooved form, the grooves being clearly shown at d in The guide portion 2 however, accurately fitting the guide chamber or cavity, prevents any mud or sediment from passing up into the chamber 1 and thus interferingwith the action of the impact device or clogging its action. At the same time upward movement of the piston member is not impeded at all due to the fact that the guide chamber is open to the exterior of the cylinder member so that on the upward movement of the piston member, water will pass freely into the lower portion of the cylinder member to fill the space occupied by the piston member'and will be freely expelled on the downward stroke and due to the curved and flaring shape of the port 1 the action of the loo water in passing out will wash this passage free and prevent any accumulation of sediinent therein.

lit will further be seen that the capacity of the chamber 1 remains always the same,

irrespective of the position. of the piston member, by reason of the piston following in from both ends.

Having thus described my invention, What I claim is:

1. A drill ar comprising a cylinder member having an elongated piston cavity provided with opposed contact shoulders and having a reduced guide cavity in axial alignment therewith, and a piston element having an enlarged portion in said piston cavity adapted to contact alternately with said shoulders, and having an extension fitting said guide cavity.

2. A drill jar comprising a cylinder inc nher having its lower end adapted for drill rod connection, said cylind member having a piston cavity provided with a. shoulder at its lower end, and a tubular cavity below said shoulder having a laterally opening port at its lower end, a bushing removably carried by said cylinder member at its upper end, and a piston member passing slidably through said bushing and guided at its lower end in said guide cavity, said piston member having an enlarged portion located in said piston cavity and adapted to contact alternately with said shoulder and bushing, said enlarged portion having water passages in'its Walls, and said piston memher having its upper end adapted for drill rod connection.

in testimony whereof I affix my signature.

JAMES n. emns. 

